Ive got a unissued one its my favorite pack ,but the one you linked isnt showing its external frame which id say is a must i never used mine without its frame, the pack itself obviously can be used without the frame but there are no supports in it its dense (i think) foam covered in codura the frame is great you can carry kit on it without the pack it can take a load of weight and i find it very comfy the pack is also good two big main compartments and four smaller ones plus some usefull strap to attach bed rolls etc
if you are interested there is a europe site on line that deliver to U.K and they have them complete with frame cant remeber the link off hand but will have a search,they are very tough big well made packs.